DESCRIPTION: (Verbatim from applicant's abstract) We will measure simultaneous MEG and chronic ECoG co-registered in MRI in pre-surgical patients with intractable partial epilepsy during afterdischarges, inter-ictal spikes, and, in some patients, seizures. We will use our newly installed whole cortex 68-channel neuromagnetometer and 64 EEG channels. We will compare the localization specificity and detection sensitivity of the two fields and investigate new methods of improving the MEG by studying the same event from the cortex. We will apply realistic models of the source and of the volume conductor in BrainStorm and Curry in collaboration with Drs. Mosher, Leahy, and Baillet. We will compare these new models to the standard single dipole model used clinically. We will study MEG and EEG and attempt their fusion. We will study the characteristics of live skull. We will test if realistic models add useful additional information. We will test how MEG and source analysis can enhance present noninvasive standard epilepsy pre-surgical evaluations to localize the epileptogenic zone. We will map the outer borders of hand cortex to allow more precise maps of essential areas for surgical planning. We purchased the neuromagnetometer with a shared instrumentation grant and we will make our results and lab available to several other collaborators, to enhance their research in, for instance, language and to ensure maximum utility from this costly NIH equipment.